//! Test report formatting — human-readable, JSON, and JUnit XML output.

use crate::types::{TestResult, TestStatus};

/// Aggregated report for a set of test runs.
pub struct TestReport {
    pub total: u32,
    pub passed: u32,
    pub failed: u32,
    pub skipped: u32,
    pub errors: u32,
    pub duration_ms: u64,
    pub results: Vec<TestResult>,
}

impl TestReport {
    /// Build a report from a slice of individual test results.
    pub fn from_results(results: Vec<TestResult>) -> Self {
        let total = results.len() as u32;
        let passed  = results.iter().filter(|r| r.status == TestStatus::Pass).count() as u32;
        let failed  = results.iter().filter(|r| r.status == TestStatus::Fail).count() as u32;
        let skipped = results.iter().filter(|r| r.status == TestStatus::Skip).count() as u32;
        let errors  = results.iter().filter(|r| r.status == TestStatus::Error).count() as u32;
        let duration_ms = results.iter().map(|r| r.duration_ms).sum();
        Self { total, passed, failed, skipped, errors, duration_ms, results }
    }

    /// Print a human-readable summary to stdout.
    pub fn print(&self) {
        let target_label = format!("({}ms total)", self.duration_ms);

        println!("\nRunning {} tests...\n", self.total);

        for r in &self.results {
            let icon = match r.status {
                TestStatus::Pass  => "  ok  ",
                TestStatus::Fail  => " FAIL ",
                TestStatus::Skip  => " SKIP ",
                TestStatus::Error => "ERROR ",
            };
            println!("  [{icon}] {} ({}ms)", r.name, r.duration_ms);

            // Show failing assertions
            if r.status == TestStatus::Fail {
                for (i, a) in r.assertions.iter().enumerate() {
                    if !a.passed {
                        println!("      assert {}", a.expression);
                        if let Some(actual) = &a.actual {
                            println!("        actual:   {actual}");
                        }
                        if let Some(expected) = &a.expected {
                            println!("        expected: {expected}");
                        }
                        println!("      at assertion {}", i + 1);
                    }
                }
            }
            if let Some(err) = &r.error {
                println!("      error: {err}");
            }
        }

        println!("\nResults: {} passed, {} failed, {} skipped {}", self.passed, self.failed, self.skipped, target_label);
        if self.errors > 0 {
            println!("  ({} error(s) — see above)", self.errors);
        }
    }

    /// Serialize to JSON.
    pub fn to_json(&self) -> String {
        let results: Vec<serde_json::Value> = self
            .results
            .iter()
            .map(|r| {
                let assertions: Vec<serde_json::Value> = r
                    .assertions
                    .iter()
                    .map(|a| {
                        serde_json::json!({
                            "expression": a.expression,
                            "passed": a.passed,
                            "actual": a.actual,
                            "expected": a.expected,
                        })
                    })
                    .collect();
                serde_json::json!({
                    "name": r.name,
                    "target": r.target.to_string(),
                    "status": r.status.to_string(),
                    "duration_ms": r.duration_ms,
                    "assertions": assertions,
                    "error": r.error,
                })
            })
            .collect();

        let report = serde_json::json!({
            "total": self.total,
            "passed": self.passed,
            "failed": self.failed,
            "skipped": self.skipped,
            "errors": self.errors,
            "duration_ms": self.duration_ms,
            "results": results,
        });

        serde_json::to_string_pretty(&report).unwrap_or_else(|_| "{}".to_string())
    }

    /// Serialize to JUnit XML (for CI integration).
    pub fn to_junit_xml(&self) -> String {
        let mut xml = String::new();
        xml.push_str("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
        xml.push_str(&format!(
            "<testsuite name=\"el\" tests=\"{}\" failures=\"{}\" errors=\"{}\" skipped=\"{}\" time=\"{}\">\n",
            self.total,
            self.failed,
            self.errors,
            self.skipped,
            self.duration_ms as f64 / 1000.0,
        ));

        for r in &self.results {
            let classname = "el_test";
            let time = r.duration_ms as f64 / 1000.0;
            let name_escaped = xml_escape(&r.name);

            match r.status {
                TestStatus::Pass => {
                    xml.push_str(&format!(
                        "  <testcase classname=\"{classname}\" name=\"{name_escaped}\" time=\"{time:.3}\"/>\n"
                    ));
                }
                TestStatus::Fail => {
                    xml.push_str(&format!(
                        "  <testcase classname=\"{classname}\" name=\"{name_escaped}\" time=\"{time:.3}\">\n"
                    ));
                    for a in r.assertions.iter().filter(|a| !a.passed) {
                        let msg = xml_escape(&a.expression);
                        let details = match (&a.actual, &a.expected) {
                            (Some(act), Some(exp)) => format!("actual: {act}, expected: {exp}"),
                            (Some(act), None) => format!("actual: {act}"),
                            _ => "assertion failed".to_string(),
                        };
                        let details_esc = xml_escape(&details);
                        xml.push_str(&format!(
                            "    <failure message=\"{msg}\">{details_esc}</failure>\n"
                        ));
                    }
                    xml.push_str("  </testcase>\n");
                }
                TestStatus::Skip => {
                    xml.push_str(&format!(
                        "  <testcase classname=\"{classname}\" name=\"{name_escaped}\" time=\"{time:.3}\">\n    <skipped/>\n  </testcase>\n"
                    ));
                }
                TestStatus::Error => {
                    let err_msg = xml_escape(r.error.as_deref().unwrap_or("unknown error"));
                    xml.push_str(&format!(
                        "  <testcase classname=\"{classname}\" name=\"{name_escaped}\" time=\"{time:.3}\">\n    <error message=\"{err_msg}\"/>\n  </testcase>\n"
                    ));
                }
            }
        }

        xml.push_str("</testsuite>\n");
        xml
    }

    /// Whether the overall test run passed (no failures or errors).
    pub fn is_pass(&self) -> bool {
        self.failed == 0 && self.errors == 0
    }
}

fn xml_escape(s: &str) -> String {
    s.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
        .replace('\'', "&apos;")
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::types::{AssertionResult, TestTarget};

    fn make_pass(name: &str) -> TestResult {
        TestResult {
            name: name.to_string(),
            target: TestTarget::Unit,
            status: TestStatus::Pass,
            duration_ms: 5,
            assertions: vec![AssertionResult {
                expression: "x == 42".into(),
                passed: true,
                actual: Some("true".into()),
                expected: None,
            }],
            error: None,
        }
    }

    fn make_fail(name: &str) -> TestResult {
        TestResult {
            name: name.to_string(),
            target: TestTarget::Unit,
            status: TestStatus::Fail,
            duration_ms: 3,
            assertions: vec![AssertionResult {
                expression: "x == 99".into(),
                passed: false,
                actual: Some("42".into()),
                expected: Some("99".into()),
            }],
            error: None,
        }
    }

    fn make_skip(name: &str) -> TestResult {
        TestResult {
            name: name.to_string(),
            target: TestTarget::E2e,
            status: TestStatus::Skip,
            duration_ms: 0,
            assertions: vec![],
            error: Some("ENGRAM_URL not set".into()),
        }
    }

    #[test]
    fn test_report_counts() {
        let report = TestReport::from_results(vec![
            make_pass("a"),
            make_fail("b"),
            make_skip("c"),
        ]);
        assert_eq!(report.total, 3);
        assert_eq!(report.passed, 1);
        assert_eq!(report.failed, 1);
        assert_eq!(report.skipped, 1);
    }

    #[test]
    fn test_report_is_pass() {
        let report = TestReport::from_results(vec![make_pass("a"), make_pass("b")]);
        assert!(report.is_pass());
    }

    #[test]
    fn test_report_is_not_pass_on_fail() {
        let report = TestReport::from_results(vec![make_pass("a"), make_fail("b")]);
        assert!(!report.is_pass());
    }

    #[test]
    fn test_to_json_valid() {
        let report = TestReport::from_results(vec![make_pass("test")]);
        let json = report.to_json();
        let parsed: serde_json::Value = serde_json::from_str(&json).expect("valid JSON");
        assert_eq!(parsed["total"], 1);
        assert_eq!(parsed["passed"], 1);
    }

    #[test]
    fn test_to_json_contains_results() {
        let report = TestReport::from_results(vec![make_pass("hello")]);
        let json = report.to_json();
        assert!(json.contains("hello"));
    }

    #[test]
    fn test_to_junit_xml_valid() {
        let report = TestReport::from_results(vec![make_pass("a"), make_fail("b")]);
        let xml = report.to_junit_xml();
        assert!(xml.starts_with("<?xml"));
        assert!(xml.contains("<testsuite"));
        assert!(xml.contains("</testsuite>"));
    }

    #[test]
    fn test_to_junit_xml_pass_testcase() {
        let report = TestReport::from_results(vec![make_pass("arithmetic")]);
        let xml = report.to_junit_xml();
        assert!(xml.contains("arithmetic"));
        assert!(!xml.contains("<failure"));
    }

    #[test]
    fn test_to_junit_xml_fail_testcase() {
        let report = TestReport::from_results(vec![make_fail("failing")]);
        let xml = report.to_junit_xml();
        assert!(xml.contains("<failure"));
    }

    #[test]
    fn test_to_junit_xml_skipped() {
        let report = TestReport::from_results(vec![make_skip("e2e")]);
        let xml = report.to_junit_xml();
        assert!(xml.contains("<skipped"));
    }

    #[test]
    fn test_duration_sum() {
        let report = TestReport::from_results(vec![make_pass("a"), make_pass("b")]);
        assert_eq!(report.duration_ms, 10); // 5 + 5
    }

    #[test]
    fn test_xml_escape() {
        let escaped = super::xml_escape("a < b & c > d \"e\" 'f'");
        assert!(escaped.contains("&lt;"));
        assert!(escaped.contains("&amp;"));
        assert!(escaped.contains("&gt;"));
        assert!(escaped.contains("&quot;"));
    }
}